Sixteen Democrats have promised to oppose Rep. Nancy Pelosi to be the next Speaker of the House.

In a signed letter sent to Democratic colleagues, the group said they won't vote for Pelosi during both the internal caucus vote this month or the official House floor vote in January.

The group consists of 11 House veterans, 4 newly elected representatives and one who's in a race that hasn't been called yet. They've expressed their desire for new leadership as the reason for their opposition to the California representative. The group thanked Pelosi for her "years of service," but felt their party's recent majority in the House was brought about on a message of "real change in Washington."

Despite the group's relatively small size, their lack of support could prove detrimental to Pelosi. As of right now, Democrats have a 16-seat majority in the House, meaning there's a chance Pelosi will lose if the members stick to their plans. Five other Democrats have said they will not vote for Pelosi, but did not sign the letter.

Pelosi was elected Speaker of the House over a decade ago. She lost her position in 2010 when the GOP took the House, and has served as Minority Leader ever since.